Transmitter for m echan ical telephones



(No Model.)

J. PRINCE. TRANSMITTER FOR MECHANICAL TELBPHONES.

Patented May 6, 1890.

NEESES:

UNITED STATES PATENT OEEIcE.

JEROME PRINCE, OF MILFORD, MASSACHUSETTS, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO THE GLASS TRANSMITTER TELEPHONE COM- PANY, OF MAINE.

TRANSMITTER FOR MECHANICAL TELEPHONES.

SPECIFICATION forming part of Letters Patent No. 427,269, dated May 6, 1890.

Application filed August 28, 1889. Serial No. 322,183. (No model.) I

To all whom it may concern.-

Be it known that I, JEROME PRIN CE, of Milford, in the county of lVorcester, State of Massachusetts, have invented a certain new and useful Improvement in Mechanical Telephones, of which the following is a description sufficiently full, clear, and exact to e11- able any person skilled in the art or science to which said invention appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is afrontelevation of my improved transmitter; Fig. 2, a vertical section taken 1 on line 00 w in Fig. 1; and Fig. 3, an elevation of the diaphragm, the body or mouth-piece being removed.

Like letters and figures of reference indicate corresponding parts in the different fig- 0 ures of the drawings.

My invention relates especially to transmitters for mechanical telephones; and it consists in certain novel features, as hereinafter fully set forth and claimed, the object 2 5 being to produce a simpler, cheaper, and more eifcetive device of this character than is now in ordinary use.

The nature and operation of the improvement will be readily understood by all con- 0 versant with such matters from the following explanation.

In the drawings, A represents the back plate, and B the ease or body. The back plate is constructed of wood, and is provided with 5 a wire-opening b. The case B is cylindrical in cross-section and is constructed of glass. An annular flange d is formed around one end of said case or body. The opposite end is bent or curved inward, forming a circular 4o mouth-piecef. Slots g are formed in the edge of the flanged. Screw-bolts 7L, passing through said slots into the back plate A, secure said case thereto. lVashers 2', formed of rubber or similar material, are disposed around the 5' bolts of both sides of the flange (1. Four glass lugs 70 are secured to the face of the plate A equidistant from the wire-openin g b and pro ject within the case B. A cylinder C, of copper or similar metal, fits closely within the case, one edge thereof engaging the lugs 7.1. A diaphragm D, composed preferably of daguerreotype metal, closes the outer end of the cylinder 0, and is provided centrally with a wire-opening m in alignment with the opening 1) in the plate A. The conducting-wire II passes through these openings, and a button K is secured to the outer end thereof, said button projecting into the mouth of the case. The high tension of the wire II upon said button draws it against the diaphragm andholds the cylinder 0 firmly against the lugs 7t. The sound-vibrations entering the mouthf and transmitted by the diaphragm of the wire are intensified by this construction. The glass forming the case, being in contact with the metallic cylinder to which said diaphragm is l secured, is found to greatly augment the sound-waves and render them much sharper and more distinct. The lugs 7.; may be formed on the inner face of the body 13 and integral 7o therewith, instead of on the back plate, if desired.

Having thus explained my invention, what I claim is- 1. In a transmitter for mechanical tcle- 7 5 phones, a back plate a glass case or body socured thereto, and a diaphragm secured to a metallic cylinder wit-11in said body, said cylinder being held in engagement with glass lugs on said back plate by the tension of the So conducting-wire, substantially as described.

2. In a transmitter for mechanical telephones, a glass body or mouth-piece in con tact with a metallic cylinder bearing the diaphragm, substantially as described.

3. A body or mouth-piece for a mechanical-telephone transmitter, composed of glass and adapted to contain the diaphragm, substantially as described.

a. In a transmitter for mechanical tele phones, a wooden back plate, a cylindrical glass body having an annular attaching-flange at one end, its opposite end being curved inward to form a mouth piece, glass lugs on the back plate projecting into said body, a metallic cylinder, and a diaphragm secured to one end thereof, all being arranged substantially as described.

5. In a transmitter for mechanical telephones, a cylindrical glass body provided with a mouth-piece and secured to a wooden back plate, flexible washers interposed be tween said body and plate, a metallic cylinder disposed within the body in engagement therewith, a diaphragm closing one end of said cylinder, a button secured to a conducting-Wire passing through the diaphragm and back plate, and glass lugs on said plate in engagement with the opposite end of said cylinder, substantially as described.

(3. A transmitter for mechanical telephones, comprising a cylindrical glass body, a metallic cylinder within the body in engagement therewith, and a metallic diaphragm closing one end of said cylinder, its opposite ends resting on glass lugs within said body, substantially as described.

'7. I11 a device of the character described, the combination, with the Wooden back plate A, of the glass body B, the metallic cylinder C, provided with the diaphragm D, and the glass lugs 70, arranged substantially as described.

8. In a mechanical telephone, the plate A, provided with the opening Z) and glass lugs 7;, in combination with the glass body B,secured to said plate and having the mouth f and flange d, the metallic cylinder 0, provided with the diaphragm D,having the opening m, the button K, and wire H, and the flexible washers i, interposed between said body and plate, substantially as described.

JEROME PRINCE.

\Vitnesses:

O. M. SHAW, E. F. MCGARTY. 

